The present invention relates to a radio pager adaptive to a plurality of frequency bands and, more particularly, to a radio pager capable of preventing frequency information for obtaining a desired oscillation frequency from being erroneously written thereto by identifying and reporting to a user a frequency band assigned to the radio pager before frequency information for producing a desired oscillation frequency corresponding to a reception frequency has been stored in the radio pager by an external source.
It is possible with a radio interface to obtain a radio paging service to use a plurality of different frequencies. Usually, a person intending to get the service selects one of the frequency bands in consideration of the service industry, the content of the service, and so forth and carries a radio pager adaptive to the frequency band selected. On the production line, all the radio pagers are provided with an identical basic circuit arrangement, appearance and structure, but only radio sections thereof including frequency synthesizers are each assigned to a particular frequency band. The frequency synthesizers each outputs an oscillation frequency (local oscillation frequency) adaptive to a particular receipt channel (channel frequency). After the channel or channels to be used and belonging to the frequency band have been determined, corresponding frequency information is written to a ROM (Read Only Memory). The frequency information is transformed to a frequency signal designating the oscillation frequency of the frequency synthesizer and then fed to the frequency synthesizer.
It is necessary with the above radio pagers of the same time and each being adaptive to a plurality of frequency bands with slight modification to identify the frequency band assigned to each radio pager. For the identification, it is a common practice to see a frequency printed on a label adhered to the body of the pager or to see a frequency previously stored in a ROM on a display by, e.g., pressing a button.
However, the problem is that when the frequency information is not written to the ROM, the frequency is, of course, not printed on the label of the pager body. In this condition, the operator must open the casing of the pager and see parts constituting the radio section. As a result, the operator is likely to write in the ROM frequency information other than the information actually meant for the ROM.